Carfilzomib (PR-171)

Carfilzomib (PR-171) is an irreversible proteasome inhibitor with IC50 of <5 nM in ANBL-6 cells, displayed preferential in vitro inhibitory potency against the ChT-L activity in the β5 subunit, but little or no effect on the PGPH and T-L activities.

MM.1S cells were treated with or without carfilzomib (10 nM) in the presence or absence of TAS-117 (0.5 uM) for 24 h. Whole cell lysates were subjected to western blotting using CHOP, PARP, and GAPDH Abs.The graph represents fold changes of CHOP density relative to GAPDH.

Research Area

Product Description

Biological Activity

Description

Carfilzomib (PR-171) is an irreversible proteasome inhibitor with IC50 of <5 nM in ANBL-6 cells, displayed preferential in vitro inhibitory potency against the ChT-L activity in the β5 subunit, but little or no effect on the PGPH and T-L activities.

Protocol(Only for Reference)

ANBL-6 cells (2 × 106/well) are plated in 96-well plates and treated with Carfilzomib doses from 0.001 to 10 μM for 1 hour. Cells are then lysed (20 mM Tris-HCl, 0.5 mM EDTA), and cleared lysates are transferred to polymerase chain reaction (PCR) plates. A standard curve is generated using untreated ANBL-6 cell lysates starting at a concentration of 6 μg protein/μL. The active site probe [biotin-(CH2)4-Leu-Leu-Leu-epoxyketone; 20 μM] is added and incubated at room temperature for 1 hour. Cell lysates are then denatured by adding 1% sodium dodecyl sulfate (SDS) and heating to 100°C, followed by mixing with 20 μL per well streptavidin-sepharose high-performance beads in a 96-well multiscreen DV plate and incubated for 1 hour. These beads are then washed with enzyme-linked immunosorbent assay (ELISA) buffer (PBS, 1% bovine serum albumin, and 0.1% Tween-20), and incubated overnight at 4°C on a plate shaker with antibodies to proteasome subunits. Antibodies used included mouse monoclonal anti-β1, anti-β2, anti-β1i, and anti-β5i, goat polyclonal anti-β2i, and rabbit polyclonal anti-β5 (affinity-purified antiserum against KLH-CWIRVSSDNVADLHDKYS peptide). The beads are washed and incubated for 2 hours with horseradish peroxidase-conjugated secondary goat antirabbit, goat antimouse or rabbit antigoat antibodies. After washing, the beads are developed using the supersignal ELISA picochemiluminescence substrate. Luminescent detection is performed. Raw luminescence is converted to μg/mL by comparison with the standard curve and expressed as the % inhibition relative to vehicle control. Curve fits are generated using the following nonsigmoidal dose-response equation: Y = Bottom + (Top-Bottom)/(1 + 10̂((LogEC50 − X) × HillSlope)), where X is the logarithm of concentration, Y is the % inhibition, and EC50 is the dose showing 50% effect.

WST-1 is used to determine the effects of proteasome inhibitor Carfilzomib on cell proliferation. The inhibition of proliferation is calculated in relation to parallel control cells that receives vehicle alone. A linear spline function is used to interpolate the median inhibitory concentration (IC50) using XLfit 4 software. The degree of resistance (DOR) is calculated using the formula: DOR = IC50(resistant cells)/IC50(sensitive cells). ANBL-6 cells pulsed with 100 nM carfilzomib are washed and suspended in PBS containing 5 μg/mL of JC-1, which exhibits potential-dependent accumulation in mitochondria. Analysis of the mitochondrial membrane potential-dependent color shift from 525 to 590 nm is carried out on a FacScan, and the data are analyzed with CellQuest software.

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

Species

Mouse

Rat

Rabbit

Guinea pig

Hamster

Dog

Weight (kg)

0.02

0.15

1.8

0.4

0.08

10

Body Surface Area (m2)

0.007

0.025

0.15

0.05

0.02

0.5

Km factor

3

6

12

8

5

20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by

Animal B Km

Animal A Km

For example, to modify the dose of resveratrol used for a mouse (22.4 mg/kg) to a dose based on the BSA for a rat, multiply 22.4 mg/kg by the Km factor for a mouse and then divide by the Km factor for a rat. This calculation results in a rat equivalent dose for resveratrol of 11.2 mg/kg.

* <1 mg/ml means slightly soluble or insoluble.* Please note that Selleck tests the solubility of all compounds in-house, and the actual solubility may differ slightly from published values. This is normal and is due to slight batch-to-batch variations.

To demonstrate that treatment with proteasome inhibitors other than bortezomib can also salvage missense mutated dysferlin, we treated primary myoblasts from patient 2 with either the irreversible proteasome inhibitor carfilzomib, which is the biologically active, hydrolyzed form of the investigational, reversible proteasome inhibitor ixazomib (MLN9708) being developed for oral application. It found that treatment with carfilzomib resulted in a dose-dependent increase in dysferlin expression.

MM.1S cells were treated with or without carfilzomib (10 nM) in the presence or absence of TAS-117 (0.5 uM) for 24 h. Whole cell lysates were subjected to western blotting using CHOP, PARP, and GAPDH Abs.The graph represents fold changes of CHOP density relative to GAPDH.

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Tech Support & FAQs

Answers to questions you may have can be found in the inhibitor handling instructions. Topics include how to prepare stock solutions, how to store inhibitors, and issues that need special attention for cell-based assays and animal experiments.

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